Jason Hunt

Virginia Commonwealth University | VCU ·  Department of Microbiology & Immunology

Mosquitoes are closely associated with their surrounding environment; their microbiomes can vary depending on their diet, stage of development, and environment. They can also consist of harmful and beneficial bacteria and fungus. Some of these microbial communities may have unknown roles that may affect mosquito populations, development, and vector...

Many environmental factors, such as annual precipitation, temperature variations, and the embedded stochasticity of natural systems, affect resource availability from one region to the next, such that animal survival and reproduction rates differ by region. For species exhibiting phenotypic plasticity, embedding phenotypes in a model of population...

Nontypeable Haemophilus influenzae (NTHi) has been shown to form biofilms, comprised of extracellular DNA (eDNA), in the middle ear and bronchus during clinical infections. Studies in our laboratory have shown that NTHi possesses a homolog of Staphylococcus aureus thermonuclease (staphylococcal thermonuclease), NTHi nuclease (NTHi Nuc, HI_1296). Th...

Findings from a preliminary study of the relationship(s) between yeast diversity and mosquito abundance in an urban stream.

Arboviruses, arthropod-borne viruses, have been a growing public health concern for years, and represent over 30% of identified emerging infectious diseases. West Nile virus (WNV) is an arbovirus and its main vector is the Culexmosquito, commonly known as the house mosquito. Multiple bird species serve as the primary reservoir for the virus. WNV wa...

An update on a long term study of invasive mosquitoes in the Lower Impounded and the Illinois River Reaches of the Upper Mississippi River. During the study period, we recorded the first instance of Ae. japonicus in Fulton and Schuyler Counties and provide evidence of an active populations in Fulton. Schuyler, Cass and McDonough Counties.

Nontypeable Haemophilus influenzae (NTHi) forms biofilms in the middle ear during human infection. The biofilm matrix of NTHi contains extracellular DNA. In this paper, we show that NTHi possesses a potent nuclease, which is a homolog of the thermonuclease of Staphylococcus aureus. Using a biofilm dispersal assay, studies showed a biofilm dispersal...

LPS is a major component of the outer membrane of Gram-negative bacteria. The lipid A region of LPS mediates stimulation of the immune system. In E. coli, the gene (formerly htrB) codes for a late lauroyltransferase (LpxL) in lipid A biosynthesis. E. coli lpxL mutants have been described previously with impaired growth above 33 in rich media. Howev...

Background: Studies of nontypeable Haemophilus influenzae (NTHi) have demonstrated that a number of genes associated with infectivity have long repeat regions associated with phase variation in expression of the respective gene. The purpose of this study was to determine the genes that underwent phase variation during a 6-day period of experimenta...

Neisseria gonorrhoeae has been shown to form biofilms during cervical infection. Thus, biofilm formation may play an important role in the infection of women. The ability of N. gonorrhoeae to form membrane blebs is crucial to biofilm formation. Blebs contain DNA and outer membrane structures, which have been shown to be major constituents of the bi...

Francisella tularensis is capable of rampant intracellular growth and causes a potentially fatal disease in humans. Whereas many mutational studies have been performed with avirulent strains of Francisella, relatively little has been done with strains that cause human disease. We generated a near-saturating transposon library in the virulent strain...

Figure S2 shows the positive-ion MALDI-TOF mass spectra of unprocessed capsule. The predominant monoisotopic mass observed is m/z 815, this mass corresponds to the sodiated form of the 792 Da tetrasaccharide repeating unit. These data show that we were able to detect up to six repeating units in the capsule sample. (0.21 MB TIF)

Figure S1 shows a Western Blot that demonstrates that capsule does not appear to be shed during growth into the supernate of liquid cultures. One microgram of each of the following underwent SDS-PAGE using a 4–12% gel followed by transfer to nitrocellulose. Lane 1 contains the molecule weight controls and the arrow indicates 200 kDa, lane 2 is an o...

Figure S3 shows the positive-ion vMALDI-LIT mass spectra of HF-treated capsule. After HF treatment, the predominant monoisotopic sodiated masses observed are at m/z 833 and 1625 which corresponds to one or two units of the 792 Da tetrasaccharide repeat, respectively. The fragments observed after HF treatment were generated by chemical hydrolysis an...

Capsular polysaccharides are important factors in bacterial pathogenesis and have been the target of a number of successful vaccines. Francisella tularensis has been considered to express a capsular antigen but none has been isolated or characterized. We have developed a monoclonal antibody, 11B7, which recognizes the capsular polysaccharide of F....

Lipopolysaccharide (LPS) is a major component of the outer membrane of gram-negative bacteria, and the lipid A region of LPS mediates stimulation of the immune system in a structure-dependent manner. Unlike the LPS of many other gram-negative bacteria, the LPS of Francisella tularensis isolated from in vitro cultures is not proinflammatory. This ob...

The anaphylatoxin receptors of the complement system are important in immune defense but also play a role in autoimmune disease. Reports have demonstrated induced C5a receptor (C5aR) expression in a number of disease states, yet little is known about the regulation of this gene. We have examined sequences in the presumptive promoter-enhancer region...

Acrylamide is a widely used monomer that produces peripheral neuropathy. It is metabolized to the epoxide, glycidamide, which is also considered to be neurotoxic. A new reversed-phase high-performance liquid chromatography (HPLC) method is described that permits simultaneous determination of acrylamide and glycidamide in rat plasma. Samples were de...

Long-term, low-dose (subchronic) oral acrylamide (ACR) exposure produces peripheral nerve axon degeneration, whereas irreversible axon injury is not a component of short-term, higher dose (subacute) i.p. intoxication [Toxicol Appl Pharmacol 1998;151:211]. It is possible that this differential axonopathic expression is a product of exposure-dependen...